For now EPEL have owncloud 8.0

As upstream only support update from 1 version, you need to update first to 8.1 (in "remi") and then to 8.2 (in "remi-test")

This is a backport from Fedora package.
See: ownCloud updates coming soon in Fedora

You can use this version enabling remi-test temporarily or by using the "includepkgs=owncloud" directive

Of course, I also recommends to update PHP to 5.6 by enabling remi-php56 repository.

P.S. I plan to move this version to remi and add version 9.0 in testing in a few weeks